Serum anti-PCK1 antibody levels are a prognostic factor for patients with diabetes mellitus.

"Declarations Ethics approval and consent to participateThe protocols of this study complied with the 1975 Declaration of Helsinki and were approved by the Local Ethical Review Board of Chiba University, Graduate School of Medicine in Chiba, Japan (No. 2017–251, 2018–320, 2020–1129), as well as by the Review Boards of the participating hospitals. Sera were collected from patients who provided written, informed consent. Consent for publicationNot applicable. Competing interestsThe present study was performed in collaboration with Fujikura Kasei Co. Ltd. RN and HK are employees of Fujikura Kasei Co. Ltd. All other authors do not have any competing interest. Competing interests The present study was performed in collaboration with Fujikura Kasei Co. Ltd. RN and HK are employees of Fujikura Kasei Co. Ltd. All other authors do not have any competing interest."

"Funding This work was supported, in part, by research grants from the Japan Science and Technology Agency (JST) and JSPS KAKENHI Grant Numbers 20K17953, 19K09451, 17K19810, 19K08596, 20K07810, 16K10520, 20K07810, 21K07395, and 15K10117."